Rechargeable batteries find widespread use in a number of applications. Among the many applications for rechargeable batteries is the use of such batteries in powering electric vehicles, including lift trucks, pallet jacks, tuggers, automated guided vehicles, and other electric powered people and equipment movers found in an industrial setting.
A charger for recharging batteries may be either a simple charger or a closed-loop charger. Simple chargers deliver a low level charge current to the battery over a long period of time. Closed-loop chargers deliver a high current to rapidly charge the battery, and monitor the state of the battery during charging to prevent overcharge. There are a number of methods that may be used to regulate the rapid charging of a battery. The most traditional is a constant current/constant voltage charging algorithm. Another common algorithm is a stepped (IVI) charging algorithm. Other known algorithms are also used to monitor and regulate charging.
With any application environment it is important to ensure that the battery and the charger are appropriate for the anticipated use. Many industrial applications require that electric powered vehicles operate for two or three consecutive shifts at a time without an extended recharging period. There may be various breaks for coffee, meals, or shift changes during which recharging can take place. The cyclical use of equipment in an industrial application means that the energy needs are somewhat consistent over a cycle, that there is a fixed amount of time available for recharging, and that it is important that the equipment remain operating without requiring battery changes. Therefore, it is important to select a battery and charger that are tailored to the particular energy needs and schedule for a particular electric vehicle or industrial use.
Accordingly, a need exists for a system and method for calculating an energy transfer profile based upon a particular application environment and a particular charging model.